WASHINGTON — Until he published details of New York congressman Anthony Weiner’s cyber-cheating escapades, blogger Andrew Breitbart was a middling media celebrity among U.S. conservatives, overshadowed by outsized personalities such as Glenn Beck and Rush Limbaugh.

Now he has brought down one of the most pugnacious liberal politicians on Capitol Hill, Mr. Breitbart, 42, has the spotlight to himself.

“I think we were vindicated,” he said this week. “Everything we reported was true on that story.”

It’s a statement the rightwing muckraker hasn’t always been able to make.

The one-time protégé of online rabble-rouser Matt Drudge has earned his own -somewhat dubious -reputation in recent years with no-holds-barred attacks on liberals, who he says are given a free ride by the “Democratic media complex.”

He’s a favourite of Tea Party activists, who praise him as fearless. Opponents call him an ideological “hitman” and master of the smear.

In 2009, he posted sting videos allegedly showing workers at ACORN, an advocacy group for low-income Americans, advising clients on illegal activity.

In July 2010, he published another heavily edited video on his website BigGovernment.com. This appeared to show Shirley Sherrod, a black Department of Agriculture employee, telling a National Association for the Advancement of Colored People meeting she once discriminated against a white farmer because of his race.

She was immediately fired. But a review of the full speech showed Ms. Sherrod was telling a story about overcoming prejudice -she had helped the farmer keep his land. She is now suing Mr. Breitbart.

So when Mr. Breitbart broke the “Weinergate” story on May 27 -publishing a photograph of Mr. Weiner in his underwear, along with his claims his Twitter account had been hacked -mainstream news outlets were skeptical.

Liberal bloggers went into full attack mode. Joan Walsh, editor of Salon.com, said Mr. Weiner was the victim of a “right-wing smear machine.” At CNN, legal analyst Jeffrey Toobin said Mr. Breitbart’s “stories tend to fall apart on close inspection.”

In fact, Mr. Breitbart was right. He later published new charges of Mr. Weiner’s social media mischief, triggering the congressman’s tearful confes-sion on Monday.

“I think the media was initially skeptical because it was coming from Andrew Breitbart. The mainstream media was saying, ‘You know what, we don’t know if we can trust this guy,’ ” said Dan Abrams, founder of the website Mediaite.

“And as more evidence came out, more photos came out, I think now the mainstream media is looking back and saying, ‘Look he was right and we probably should have been covering this earlier.’ ”

Even as he rails against liberal bias in the media, Mr. Breitbart has displayed an eagerness to engage with his ideological foes. He appeared recently on the comedian Bill Maher’s HBO program, joking with the liberal host in a collegial fashion Messrs. Limbaugh and Beck never would.

He also co-operated on the Weiner story with ABC News, but he says he has limits in what he is willing to expose.

In a goodwill gesture, he promised not to release a more-damaging, X-rated photograph he claims to have of Mr. Weiner unless the lawmaker’s liberal friends attempt to smear him or the women involved.

“I am not the cruel person that the media and certain people on the left think that I am,” he told CNN.

But on Wednesday, two U.S. satellite radio hosts published a photo they said was of Mr. Weiner -captured from a cellphone picture they said Mr. Breitbart had showed to them.

Mr. Breitbart’s desire for respect -and redemption -was evident Monday, when he appeared at the Manhattan hotel where Mr. Weiner planned to hold his apologetic news conference.

“Quite frankly I’d like an apology for him being complicit in a ‘blame the messenger’ strategy,” he said, with indignation.